1. Field of the Invention
The present invention relates to an electronic device, particularly to power saving in a battery-operated electronic device. Such an electronic device can be a cell phone, a personal intelligent communicator, a personal digital assistant, a handheld PC, a palm-top PC, or any other suitable electronic device.
The present invention further relates to an integrated circuit for such an electronic device, particularly to an integrated circuit being an audio codec.
The present invention further relates to a method of operating an electronic device.
2. Description of the Related Art
Intel™'s AC '97 Component Specification, “Audio Codec '97”, Revision 2.1, May 22, 1998, pp. 13–16, and 45–48 specifies a 16-bit full-duplex stereo audio codec (DAC and ADC) with line-level stereo inputs, a microphone input, and other inputs and outputs. As described on pages 13–15 of the AC '97 Specification, the audio sampling rate may be fixed or variable. On page 45 of the AC '97 Specification, in Table 19 powerdown control bits are shown controlling various power down modes in which blocks of the audio codec are powered down, such as input ADCs, outpout DACs, or the like. On pages 46 and 47 of the AC '97 Specification such low power modes are described in more detail.
More generally, selective powering down of circuit blocks, or running circuit blocks at reduced power, is well-known, in ICs, or in portable electronic devices using such ICs, such as cell phones, PDAs, or any other portable electronic device where there is a need to manage power consumption in order to extend battery life.